It turns out that the crucified cat photo is real, but it has nothing to do with Muslims. It is actually a photo from Ghana which surfaced last year, and features a group of men believed to be Christians, performing a crucifixion on a cat they thought was a demon. Once again, it always helps if people research information before blindly posting it around.
One such person who has done their research is Sheila Musaji of The American Muslim. She has written a good article on this topic, which also exposes the long history of Robert Spencer and Pamela Geller in fabricating outrageous False Claims against Muslims and Islam. You can read the true original story (here)